One of the most useful pieces of information on any wine label is hidden in the small print, whether on the front or back label: the percentage of alcohol it contains.

A wine’s alcohol content must be listed on most wine labels and correlates well enough to many wine traits to serve as a loose indicator of style.

Why? In dry wines (where no grape sweetness is preserved), there is a nearly direct relationship between grape ripeness and alcohol content. As a result, there’s a lot we can predict about how any given wine will taste just by knowing that 13.5% to 14% is the norm.

Wines with higher alcohol will always feel richer in texture than average, but they are also likely to taste less acidic and be more concentrated in flavor, simply due to greater ripeness.

The reverse is true for dry wines with lower alcohol, which are lighter in weight as a rule, and typically more tart and milder in
flavor.

The predictive power of alcohol content doesn’t stop there.

Some wine factors that are entirely under human control, such as degrees of new oak flavor or carbonation, are associated with higher or lower degrees of ripeness (and therefore alcohol content) for purely aesthetic reasons. The likelihood that a wine will taste oaky increases greatly with higher alcohol levels, for example, while a lower-than-average alcohol level increases the chances of encountering a prickle of carbonation.

There are exceptions to these rules of thumb, of course, and wine qualities are the least foreseeable in the crowded middle ground between 13.5% and 14%, but these patterns hold true enough to help beginners make expert-level “educated guesses.”

It’s also helpful to know that the farther a wine’s alcohol levels deviate from the more accurate these rules are.

Marnie Old is one of the country’s leading wine educators. Formerly the director of wine studies for Manhattan’s French Culinary Institute, she is best known for her visually engaging books published by DK – the award-winning infographic Wine: A Tasting Course for beginners and the tongue-in-cheek He Said Beer, She Said Wine.